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M Husain

Publications and source records attributed to M Husain.

At least 19 recordsLinked to original sources
PubMed2007

Dumbbell-shaped paraganglioma of the cervical spine in a child.

Paragangliomas are tumors arising from extra-adrenal paraganglia and account for 0.3% of all neoplasms. The carotid body and temporal bone are the most frequent sites of paraganglioma, though it has been reported to occur in almost every part of the body. Spinal paragangliomas are uncommon and mainly take the form of intradural compression of the cauda equina or thoracic cord. Extradural paragangliomas are still rare; only few cases involving the dorsolumbar spine have been reported. We are reporting an interesting case of a dumbbell-shaped primary extradural paraganglioma of the cervical spine in an 8-year-old boy that presented with progressively increasing spastic quadriparesis.

Cervical Vertebrae↗
PubMed2006

Visual neglect after right posterior cerebral artery infarction.

OBJECTIVES: To investigate the characteristics and neuroanatomical correlates of visual neglect after right-sided posterior cerebral artery (PCA) infarction. METHODS: 15 patients with acute PCA strokes were screened for the presence of neglect on a comprehensive battery of cognitive tests. Extra tests of visual perception were also carried out on six patients. To establish which areas were critically associated with neglect, the lesions of patients with and without neglect were compared. RESULTS: Neglect of varying severity was documented in 8 patients. In addition, higher-order visual perception was impaired in 5 of the 6 patients. Neglect was critically associated with damage to an area of white matter in the occipital lobe corresponding to a white matter tract connecting the parahippocampal gyrus with the angular gyrus of the parietal lobe. Lesions of the thalamus or splenium of the corpus callosum did not appear necessary or sufficient to cause neglect, but may mediate its severity in these patients. CONCLUSIONS: PCA stroke can result in visual neglect. Interruption of the white matter fibres connecting the parahippocampal gyrus to the angular gyrus may be important in determining whether a patient will manifest neglect.

Aged↗
PubMed2006

Prevalence and social correlates of postnatal depression in a low income country.

BACKGROUND: Postnatal depression is an important public health problem worldwide. Recent evidence suggests that rates may be relatively higher in developing countries. We aimed to explore the prevalence of postnatal depression and its association with social support and other risk factors in a sample of Pakistani women. METHODS: Population-based survey of 149 women at 12 weeks postnatal using the Edinburgh Postnatal Depression Scale (EPDS), Multidimensional Scale of Perceived Social Support (MSPSS) and Personal Information Questionnaire (PIQ). RESULTS: Thirty six percent women scored > or =12 on EPDS. High depression score was associated with lower social support, increased stressful life events in the preceding year and higher levels of psychological distress in the antenatal period. CONCLUSIONS: There is a high prevalence of postnatal depression in Pakistani women. Early interventions should be developed that target the antenatal period and strengthen social support networks in women at risk.

Adolescent↗
PubMed2005

A comparative study of fine needle aspiration cytology versus non-aspiration technique in thyroid lesions.

The present study was done to explore the diagnostic yield by the non-aspiration technique as compared with fine needle aspiration cytology (FNAC) of lesions in the thyroid gland. This method of non-aspiration fine needle cytology, which utilizes no active suction or aspiration, was performed on 150 patients presenting with enlargement of the thyroid gland. Smears were then cytologically assessed as unsuitable, diagnostically adequate or diagnostically superior, without knowledge of the sampling method employed. Diagnostically superior specimens were obtained significantly more frequently by the non-aspiration technique in 136 benign lesions and 14 neoplasms. Thus, the non-aspiration technique combined with FNAC can result in obtaining good quality cellular material in thyroid lesions.

Biopsy, Fine-Needle↗
PubMed2005

Cognitive processes in saccade generation.

The analysis of saccades offers an opportunity to study a number of different cognitive processes, such as visuospatial attention, working memory, and volitional conflict. A study of saccades in patients with visuospatial hemineglect, who performed a visual search task, showed repeated fixations on targets previously discovered, yet they often failed to retain the information that a particular target had previously been discovered. High-resolution structural brain scanning showed that this abnormality was due either to a lesion in the right intraparietal sulcus or the right inferior frontal lobe. Detailed analysis of the scanpaths suggested that the former location was associated with an accumulating impairment in remapping target locations across saccades or impaired memory of previously inspected target locations, whereas the latter location was more consistent with a failure to inhibit responses to rightward locations. When combined with a spatial bias to the right, such deficits might explain why many neglect patients often reexamine rightward targets, at the expense of items to their left. The functions of the supplementary eye field (SEF), in the medial frontal lobe, in relation to saccade generation are controversial. A series of studies in a patient with a focal lesion of the right SEF has indicated an important role for the SEF in the rapid self-control of saccadic eye movements and in set-switching (i.e., implementing control in situations of response conflict when ongoing saccadic plans have to be changed rapidly), rather than monitoring errors. In a recent fMRI study of normal subjects, it was shown that the SEF is involved in implementing the resolution of any volitional conflict, whereas other presupplementary motor areas are involved in the generation of volitional plans and processing volitional conflict.

Brain Mapping↗
PubMed2004

Effects of cholinergic enhancement on visual stimulation, spatial attention, and spatial working memory.

We compared behavioral and neural effects of cholinergic enhancement between spatial attention, spatial working memory (WM), and visual control tasks, using fMRI and the anticholinesterase physostigmine. Physostigmine speeded responses nonselectively but increased accuracy selectively for attention. Physostigmine also decreased activations to visual stimulation across all tasks within primary visual cortex, increased extrastriate occipital cortex activation selectively during maintained attention and WM encoding, and decreased parietal activation selectively during maintained attention. Finally, lateralization of occipital activation as a function of the visual hemifield toward which attention or memory was directed was decreased under physostigmine. In the case of attention, this effect correlated strongly with a decrease in a behavioral measure of selective spatial processing. Our results suggest that, while cholinergic enhancement facilitates visual attention by increasing activity in extrastriate cortex generally, it accomplishes this in a manner that reduces expectation-driven selective biasing of extrastriate cortex.

Acetylcholine↗
PubMed2004

Higher succinate than acetate levels differentiate cerebral degenerating cysticerci from anaerobic abscesses on in-vivo proton MR spectroscopy.

We present three patients with large intraparenchymal isolated degenerating cysticerci in whom the diagnosis was primarily based on in-vivo proton MR spectroscopy, and subsequently confirmed histologically. We suggest that the presence of succinate alone or more succinate acetate indicates the presence of degenerating cysticerci and differentiates them from anaerobic brain abscesses, which show acetate alone or in higher concentration than succinate, even when the clinical and imaging features are similar.

Acetates↗
PubMed2004

Magnetic brain stimulation can improve clinical outcome in incomplete spinal cord injured patients.

STUDY DESIGN: Preliminary longitudinal clinical trial. OBJECTIVES: To test the efficacy of repetitive transcranial magnetic stimulation (rTMS) in modulating corticospinal inhibition and improving recovery in stable incomplete spinal cord injury (iSCI). SETTING: National Spinal Injuries Centre, Stoke Mandeville Hospital, Bucks, UK and Division of Neuroscience, Imperial College Faculty of Medicine, Charing Cross Hospital, London, UK. METHODS: Four stable iSCI patients were treated with rTMS over the occipital cortex (sham treatment) and then over the motor cortex (real treatment). Patients were assessed using electrophysiological, clinical and functional measures before treatment, during sham treatment, during the therapeutic treatment and during a 3-week follow-up period. RESULTS: Cortical inhibition was reduced during the treatment week. Perceptual threshold to electrical stimulation of the skin, ASIA clinical measures of motor and sensory function and time to complete a peg-board improved and remained improved into the follow-up period. CONCLUSION: In this preliminary trial, rTMS has been shown to alter cortical inhibition in iSCI and improve the clinical and functional outcome. SPONSORSHIP: This work was supported by the International Spinal Research Trust.

Adult↗
PubMed2004

A retrospective study of multiple interbody grafting and long segment strut grafting following multilevel anterior cervical decompression.

A retrospective study of 201 patients who underwent multilevel anterior cervical decompression and fusion by multiple interbody grafting and long segment strut grafting without plate fixation was conducted from January 1991 to December 2001. Previous studies have reported lower fusion rates for anterior cervical decompressions reconstructed with multiple interbody grafts as opposed to a single long strut graft. Our aim was a retrospective study of two fusion techniques with reference to radiological and clinical outcomes in patients operated by the senior author. Of 132 patients who underwent strut grafting, 124 achieved solid fusion (93.9%), whereas 48 of 69 patients who underwent multiple interbody grafting (69.6%) achieved solid fusion. There were five cases of graft displacement or extrusion among strut-grafted patients and one among patients with interbody grafts. More 'good' and 'excellent' clinical outcomes were found among patients who underwent strut grafting (87.1 v. 81.1%). Patients with pseudoarthrosis had significantly poorer clinical outcomes. Therefore, corpectomy or vertebrectomy and strut grafting should be considered after multilevel anterior cervical decompression to increase the likelihood of successful fusion and to improve clinical outcome.

Adolescent↗
PubMed2004

Group study of an "undercover" test for visuospatial neglect: invisible cancellation can reveal more neglect than standard cancellation.

Visual neglect is a relatively common deficit after brain damage, particularly strokes. Cancellation tests provide standard clinical measures of neglect severity and deficits in daily life. A recent single-case study introduced a new variation on standard cancellation. Instead of making a visible mark on each target found, the patient made invisible marks (recorded with carbon paper underneath, for later scoring). Such invisible cancellation was found to reveal more neglect than cancellation with visible marks. Here we test the generality of this. Twenty three successive cases with suspected neglect each performed cancellation with visible or invisible marks. Neglect of contralesional targets was more pronounced with invisible marks. Indeed, about half of the patients only showed neglect in this version. For cases showing more neglect with invisible marks, stronger neglect of contralesional targets correlated with more revisits to ipsilesional targets for making additional invisible marks upon them. These results indicate that cancellation with invisible marks can reveal more neglect than standard cancellation with visible marks, while still providing a practical bedside test. Our observations may be consistent with recent proposals that demands on spatial working memory (required to keep track of previously found items only when marked invisibly) can exacerbate spatial neglect.

Aged↗
PubMed2004

Hemispatial neglect.

The syndrome of hemispatial neglect is characterised by reduced awareness of stimuli on one side of space, even though there may be no sensory loss. Although it is extremely common, it has proven to be a challenging condition to understand, and to treat. New insights from detailed behavioural and anatomical studies in patients, as well as functional imaging in healthy individuals, have begun to reveal some of the component deficits underlying the disorder. This review focuses on important clinical issues in neglect, including bedside diagnostic tests and emerging therapeutic and rehabilitation methods, involving both behavioural and drug treatments.

Brain↗
PubMed2003

Prism adaptation can improve contralesional tactile perception in neglect.

The authors show that prismatic adaptation can reduce tactile inattention in stroke patients with unilateral neglect. Four patients with visuospatial neglect and tactile extinction underwent 10-minute application of 20 degrees right-shifting prismatic lenses during pointing. This improved contralesional tactile perception in all patients, even for a task requiring no exploration or spatial motor responses. This finding suggests a potential role for prismatic adaptation in the rehabilitation of multiple sensory modalities in patients with neglect.

Adaptation, Physiological↗
PubMed2003

Neuro-endoscopic surgery--experience and outcome analysis of 102 consecutive procedures in a busy neurosurgical centre of India.

BACKGROUND: Neuro-endoscopic surgery is finding increasing application for various clinical conditions. We present our experience of 100 cases of diverse intracranial lesions, including infections, managed by neuro-endoscopy in a busy neurosurgical department in the developing world. MATERIAL AND METHODS: One hundred patients treated from March 1996 to February 2002 formed the study group. Management of hydrocephalous by Endoscopic third ventriculostomy (ETV) was the aim in 75 patients with or without diagnostic biopsy. Excision or resection was attempted in 25 patients with juxtaventricular or intraventricular lesions. Endoscopic procedures included total tumour resection, partial resection, biopsy, stent placement, Monroplasty, septostomy and third ventriculostomy. Outcomes of endoscopic surgery were evaluated with respect to clinical and/or radiological improvement, complications and need for additional therapy. FINDINGS: Endoscopy was the only surgical treatment in 59 patients. Intermittent lumbar drainage for cerebrospinal fluid leak, shunt, microsurgery and/or repeat endoscopic surgery were additional treatments needed in 39 patients, who subsequently had increased hospital stay, postoperative morbidity and a higher cost of treatment. Peroperative bleeding due to distorted anatomy and obscured vision in 2 patients with post-infective loculated hydrocephalus (LH) resulted in two fatalities (2%) in the early post-operative period. INTERPRETATION: Neuro-endoscopic surgery cuts down operative time and hospital stay, reduces cost and results in a faster turnover of the patients. It is a versatile and useful tool for a busy neurosurgical department.

Adolescent↗
PubMed2003

From molecules to mammals: what's NOS got to do with it?

Nitric oxide synthases (NOSs) generate nitric oxide (NO) and the by-product l-citrulline, via the catalytic combination of l-arginine and molecular oxygen. In mammals, there are three NOS genes: nNOS (NOS1), iNOS (NOS2) and eNOS (NOS3). The molecular structure, enzymology and pharmacology of these enzymes have been well defined, and reveal critical roles for the NOS system in a variety of important processes. The studies of NOS enzymes using knockout and transgenic mouse models have provided an invaluable contribution, highlighting critical roles in neuronal, renal, pulmonary, gastro-intestinal, skeletal muscle, reproductive and cardiovascular biology. This review will outline the data gleaned from complementary knockout and transgenic over-expression models in mice, and focus on the interactions between NOS enzymes and pathophysiology of the vascular system. These studies are a paradigm for the near future, which will involve the translation of an enormous amount of genomic data into physiological insights that penetrate the realms of both health care and biology.

Animals↗
PubMed2003

Platelet 3H ketanserin binding in tension-type headache.

OBJECTIVE: The present study was undertaken to investigate the alterations in platelet 5-HT2 receptor binding in patients with tension-type headache. BACKGROUND: Serotonin (5-HT) has an important but complex role in pain modulation. The involvement of serotonin in tension-type headache has been investigated by studying serotonin in peripheral blood, but results have been inconclusive. There are, however, only a few investigations in which the status of platelet serotonin transporters has been studied by 3H imipramine and 3H paroxetine. The present study was undertaken to investigate alterations in platelet 5-HT2A receptors using 3H ketanserin as a ligand. METHODS: Platelet 3H ketanserin binding was studied in 14 patients with tension-type headache and in 15 healthy controls. The binding characteristics, equilibrium dissociation constant and maximal number of binding sites were determined by Scatchard analysis. RESULTS: There was no change in the equilibrium dissociation constant in the patients with headache as compared to the control group, but subgroup analysis revealed that patients with tension-type headache with a headache index of less than 360 had a significantly lower equilibrium dissociation constant as compared to those with a headache index of more than 360; there was a significant correlation between the equilibrium dissociation constant and the headache index. A significant decrease was observed in the maximal number of binding sites in tension-type headache. No correlation was observed between the maximal number of binding sites and age, duration of illness, or headache intensity. CONCLUSIONS: The findings of the present study show that there is a decrease in the number of binding sites of 5-HT2A receptors in some patients with tension-type headache, suggesting postsynaptic serotonergic dysfunction and the involvement of serotonin in that group.

Binding Sites↗
PubMed2003

Is neurocysticercosis a risk factor in coexistent intracranial disease? An MRI based study.

BACKGROUND: Previous reports have suggested that neurocysticercosis is associated with glioma and Japanese encephalitis, and that it is a risk factor for stroke. OBJECTIVE: To determine if neurocysticercosis has a significant association with, or is a risk factor for, coexistent pathologies such as Japanese encephalitis, glioma, abscess, tuberculoma, or infarction. SUBJECTS: 10 350 patients from the hospital population who underwent 1.5 T cranial magnetic resonance imaging during the previous 12 years were evaluated for the presence of neurocysticercosis and coexisting pathology. DESIGN: Retrospective cohort analysis. RESULTS: The prevalence of neurocysticercosis in cases with dual pathology was significantly less than in a control group (1.1% v 8.3%; z = 11.05; p < 0.001, power of test = 1). Neurocysticercosis lesions were less common (p < 0.05) in the different subgroups of coexistent pathology than in the control group except in the case of Japanese encephalitis, where the difference was non-significant (z = 0.69, p = 0.49). The relative risk was less than 1 in all subgroups except Japanese encephalitis, where it was 1.23. The location of neurocysticercosis lesions and the presence of perilesional oedema did not affect coexistent lesion location or severity on a particular side (p = 0.413 and 0.623 for location and perilesional oedema, respectively). When the above factors were analysed separately in patients with Japanese encephalitis, they also did not affect coexistent lesion location or severity (p = 0.659 and 0.548, respectively). CONCLUSIONS: The coexistence of neurocysticercosis and other lesions may be an incidental observation in a few patients referred from areas of high prevalence and endemicity. It appears unlikely that neurocysticercosis is a risk factor for other intracerebral pathology. The location of neurocysticercosis lesions and whether or not there is surrounding perilesional oedema do not appear to affect the location or severity of coexisting lesions.

Adolescent↗